Furnace



Patented Oct. 18, 1927.

' UNITED STATES P'ATE-NT OFFICE.-

ALBERT N. '1IS, 0F SCHENECTADY, NEW YORK, ASSIGNOR T0 GENERAL ELECTRIC COMPANY, A CORPORATION or NEW YORK.

. FURNACE.-

Application filed July 16, -1925. Serial No. 44,106.

My invention relates to furnaces and the like, and has for its object the provision of a simple, reliable and efficient means for applying and removing the cover.

My invention has particular application in the operation of the heavy heat insulated covers which are used on. vertical electric furnaces, melting pots, etc. In carrying out my invention I provide means whereby the coger is first lifted and then swung to one si e.

For a more complete understanding of my invention reference should be had to the accom anying drawing in which Fig. 1 is a vertical section view of an electric furnace embodying my invention, the cover being shown in closed position; Fig. 2 is a fragmentary vertical section view showing the cover in raised position, Fig. 3 -is a plan 20 view showing the cover partially swung to one side, while Fig. 4 is a fragmentary view showing a modified form of my invention.

Referring to the drawing, I have shownmy invention in.one form as applied to an 25 electrically heated furnace of the vertical type, i. e., the furnace opening is at the top; The heating chamber 11 is cylindrical in form, the central axis of the cylinder being substantially vertical. This chamber is defined at'the sides by an inner layer of heat refractory bricks 12 which are surrounded by suitable powdered heat insulating material 13, similar bricks being provided. at the bottom, and the whole being onclosed in a metallic casing or iacket 14. Resting on the bricks 12 is a heavy heat refractory member 15 provided with a'central opening 16 through which. access is had to the furnace chamber. A suitable insulating packing-material 17 is provided around the member 15, an annular space of trough being left above the packing 17 which is filled with loose sand 18. L

A circular flat cover19, suitably heat insulated, rests on the member 15. This cover consists of an outer ring shaped metallic member 20 having an internal flange 21 near its lower edge which restson the outer edge of the member 15. The ring member 20 exrin 22 which is forced downward into the san 18 when the cover is put in place, as

tends downward beyond the flange 21 for.

indicated in Fig. 1. Preferably the upper end of the member 15 is beveled, as indicated by the reference numeral 23, so as to have substantially the same incline as the inner wall of the sealing ring 22. The sealing rin 22 is somewhat larger than the upper bevele end of the member 15, the space between them being filled with the loose sand. A. circular slab 24 of suitable heat insulating material is supported on the flange 21. This slab extends over the mouth 16 ofthe furnace and rests on the member 15, its lower face being flush with the lower side of the flange 21. Above the slab 24 the ring 20 is filled with powdered heat insulating material 25, and the ring is closed at the top-by means of a circular metallic plate 26.

Any suitable heating means may be provided for the furnace. As shown, the furnace is heated by means of two electric re-. sisters 27 and 28 which are bent in zigzag form into a series of loops and hung on pins 27 secured to the bricks 12. These resistors are placed one above the other in the interior of the furnace chamber, and each extends circumferentially around the chamber. The depending loops 28 of the resistors are spaced by means of insulators 29 carried by iuitable pins which are secured to the bricks For the purpose of facilitating the removing and replacing of the cover 19, I have provided a substantially horizontal arm 29 which is pivotally mounted at one end on a bracket 30 secured to the side of the furnace. As shown, the bracket 30 is provided with a 90 substantially vertical pivot post 31 on which the arm 29 swings. Mounted on the arm 29 is a second arm 32, this arm being pivotall connected to the arm 29 at a point 33 whic is adjacent or near the pivoted end of the arm 29. The free'end of the arm 29 is forked, it being provided with two parallel projections 34 and 35. A link member 36 extends vertically between the projections 34 and 35 and has its upper end pivotally connected to the arm 32, and its lower end pivotally connected to a central lug 37 on the cover 19. A lever 38 is pivoted near one end at point'39 between the ends of the projections 34 and 35. The two portions 38" .and 38 of the lever 38 are at an angle with respect to each other which is somewhat less than 90 degrees, and when the cover is in place the shorter portion 38 underneath the arm 32 is substantially horizontal as indicated in Fi 1, the longer portion 38? then extending su stantially vertically upward. A' roller 39 is provided on the extremity of the shorter portion 38 In the operation of this mechanism, when it is desired to remove the cover, lever 38 is pulled down to a substantially horizontal position, as indicated in Fig. 2. This raises the shorter portion 38 whereby the arm 32 is raised, the roller 39 hearing against the lower edge of the arm 32. When the cover is in raised position, as shown in Fig. 2, it will be observed that the longer portion 38 of the lever 38 is substantially horizontal, and extends across the furnace in position to be conveniently grasped by the operator to swing the arm 29 to one side and thereby move the cover to one side of the furnace opening.16.' The shorter portion 38 is then inclined sl'ghtly with the vertical toward the left, as vi ed in Fig. 2, whereby the weight of the door tends to turn the lever 38 in a counterclockwise direction. .Further turning of the lever 38 in a counterclockwise direction is prevented, however, by means of projections or flanges 40 extending from each side of the arm near-its pivot which abut against flattened portions 41 on the ends of the projections 34 and 35 of the lever. When the cover is in loweredposition, as indicated in Fig. 1, the arm 38 rests against the end of the arm 32.

A small switch 42 is mounted on the arm 29 just above the arm 32. This switch is operated by means of a button 43 which is in position to be engaged by the arm 32 and moved upward to open the switch when the cover is lifted." The switch is, biased to closed position, and when the cover is lowered it again closes. This switch is connected by means of conductors. led through a flexible conduit 44 in the control circuit for the heating resistors so that when the cover is lifted this control circuit is opened and the resistors deenergized.

In the modified form of my invention shown in Fig. 4 the cover 45 is secured centrally to a vertical rod 46 having its upper end threaded. This rod extends loosely through an aperture provided for it in the swinging arm 47, adjacent the end of the arm, and cooperates with a bevel gear nut 48 resting on the arm 47 It will be understood that the arm 47 is mounted to swing over the furnace in the same manner as the arm 29 of Figs. 1, 2 and 3. The bevel gear 48 .may be turned to lift the cover by means of a handwheel 49 which turns a'horizontal 50 rotatably Inc-tinted en the e f the.

While I have described my invention as.

embodied in concrete form and as operating in a specific manner in accordance with the provisions of the patent statutes, it should be understood that I do not limit my invention thereto, since various modifications thereof will suggest themselves to those skilled in the art without departing from the spirit of my invention, the scope of which is set forth in the annexed claims.

What I claim as new and desire to secure by Letters Patent of the United States, is:

1. The combination with a furnace, of a cover for said furnace, an arm supported at one side of said furnace so as to swing over said furnace, a second arm pivoted on said first arm extending lengthwise thereof, a connection between said second arm and said cover, and a lever pivoted on the end of said first arm and acting on said second arm to lift said cover.

2. The combination with a furnace, of a 1 cover for said furnace, an arm supported.

tion acting on said second arm to raise said cover when said longer portion is moved from a substantially vertical to a substantially horizontal position.

3. The combination with a furnace, of a cover for said furnace, an arm sup orted on one side of said furnace so as to swing over said furnace, a second arm pivoted on said first arm, a connection between said second arm and said cover, and a lever pivoted on said first arm having a shorter portion engaging said second arm to raise said cover, said shorter portion being in an inclined po-, sition when the cover is lifted whereby the weight of said cover tends to turn said lever in one direction, and meansfor limiting the movement of said lever in said direction.

In witness whereof, I have hereunto set my hand this 15th day of July, 1925 it. Of

' the same may conform to the record of the casein the Patent Oflice.

. r Certific ete of I Correction. Patent No. 1, 46,213. v

ALBERT N. OTISI Granted October 18;1997, to

It is hereby certified that error appears in the grinted speeifieatipn oftheahovenumbered patent requiring correction as follows: age 1, line 41, for the Word of read or; page 2, line 102, claim 2, after the syllable ranged insertthe word at," and that the said Letters Patent should be read with these corrections therein 'that' ,1 Signedand sealeii this 6th day of December, A. D. 1927. 1 4 [3mm] j M. J. MOORE Acting Uommz'ssiomr of Pditeflts. 

